Ozone (O3) is a gas with strong oxidation properties that has been used for domestic water treatment in Europe since the early 1900's. Ozone is produced by high-intensity ultraviolet (UV) light or by a high-voltage electric field. The normal byproduct of ozone is oxygen (O2). Ozone is created when either UV or a corona discharge (CD) is applied to oxygen. The oxygen disassociates into single oxygen atoms which recombine into ozone. Ozone has a half life of about 2 to 12 hours in air and about 20 minutes when dissolved in water. Ozone is 13 times more soluble in water than oxygen. Ozone oxidizes and disinfects and deodorizes. Ozone also micro-flocculates iron and manganese and kills bacteria 3,000 times faster than chlorine, kills viruses, algae spores, and some parasites, precipitates heavy metals, controls formation of scales, and oxidizes oils. Ozone also has a fresh smell like that of an electrical storm.
Typical ozone application into water to be treated has been provided by simply bubbling ozone and air into a tank of water with the use of a diffuser (known as an ozone aeration system) or by a venturi eductor used in conjunction with a water pump. Passing water through a venturi eductor creates a suction which draws in ozone and mixes the ozone gas with water. The ozone gas is introduced into a contact tank where undissolved ozone gas is vented or is introduced directly into a storage tank and bubbles up through the tank and out the top of the tank. This same type of system has been used in swimming pools and spas, introducing the ozone into the pool or spa. In some cases, spa applications have used existing “spa hydrotherapy jets” as the means to “suck in” the ozone gas and mix the gas with the spa water.
Ozone water treatment systems have been in use for over 100 years in many applications including the pool and spa industry as well as treating water in water storage tanks. Ozone is used in combination with various chemicals in the pool and spa industry. Ozone is used to treat iron, manganese, and hydrogen sulfide in well water and to kill pathogens in surface waters such as lakes and streams. Ozone systems come in many varieties and ozone is produced in many ways.
Systems for water storage tanks are designed to clean “raw” water, whereas systems for pools and spas are designed to keep treated water clean as it is used over and over again. Prior art systems focus on using ozone and a filter to treat a reservoir of water. One prior art system adds a “mixer” assembly and a lift tube to mix ozone and new water coming into the reservoir. Such a prior art system is disclosed in U.S. Pat. No. 5,190,648 to Ramsauer, issued Mar. 2, 1993.
The Ramsauer system discloses a lift tube positioned in a single tank or reservoir. Air containing ozone generated by the ozone generator is injected into the bottom of the lift tube using a diffuser, which causes the ozonated air to be converted to bubbles. The ozonated air bubbles up through the water in the lift tube and into the tank and can escape through the top of the tank. As taught in Ramsauer, the lift tube is part of an in-the-tank filter module. The ozone gas mixing and filtration and circulation are accomplished within the filter module assembly. The action of the bubbles rising and expanding in the lift tube causes a current flow, which causes the water to be first drawn through the filter where the water is filtered with each pass and thereby prefiltering the water prior to its contact with the ozonated air. This increases the ability of the ozone to do its job.
The single reservoir design known in the art is simple to install and requires no cutting into the wall of the pool, spa, or tank to install separate lines. However, the “single” reservoir system is more difficult to maintain, because the filter needs to be pulled from the reservoir for cleaning and maintenance. In addition, the Ramsauer system does not treat the capturing ozone emanating from the reservoir after treatment, for destruction or to channel it elsewhere for some other use. There is no mechanism for preventing the user from being exposed (when used in pools and spas) to the damaging effects of ozone on an individual's mucus membranes.